JFET Applications

JFET has a many applications in electronics and communication field .Some applications of JFET described as following:

JFET buffer amplifier:

It is a one type of amplifier.This JFET amplifier isolates preceding amplification stage from the following amplification stage.A JFET acts as an well buffer amplifier because of the high impedance on output (i.e loading of the preceding stage is high ).This allows the almost whole output from first amplification stage to enter at the buffer input stage.The heavy loads drive by low out put impedance of JFET.This indicates that entire output from the buffer stage reaches the input circuits of the next amplification stage in a JFET buffer amplifier.

JFET phase-shift oscillators:

In the BJT phase-shift oscillators there is appears loading effect because of low input impedance of BJT .To minimise the loading effect in phase-shift oscillators ,the high input impedance of JFET is used in this phase-shift oscillators.

JFET used as RF amplifier:

JFET RF amplifier is used in many electronics and communication field in receiver instead of BJT RF amplifier because of following reasons;

• JFET has very low noise level.In JFET RF amplifier in receiver JFET will not produces significant value of noise in JFET RF amplifier.
• JFET is good respond to low current signal generated by the antenna because of JFET is voltage controlled semiconductor devices .SO JFET used as RF amplifier in receiver section in communication or broadcasting field.